Health Service Co-Design


The biggest difference

The biggest difference tool provides evidence of improvement to a patient's experience.

It also helps identify the key aspects of the experience that have been (or will be) changed and what part of the service made (or is likely to make) the difference.

Why use it

This tool is important because it focuses on the patient's experience. It is designed to allow you to explore an improvement without needing detailed knowledge of the 'original' (pre-improvement) experience. But with this knowledge, it does allow you to compare and contrast the new experiences with the original.

When to use it

You can use this tool to evaluate a prototype or pilot version of an improvement, or to monitor the performance of an improvement after implementation.

1. Identify the key users of the improvement

(Patients are used as a general group in the steps below)

Make sure you have identified the types of patients an improvement is designed for. It pays to select a range of types to check the improvement is working equally well for all, or to assess that it is working best for those who need it most (without compromising the service for others).

2. Have patients experience the improvement

You can set up the experience by using prototyping, or by working with patients who have experienced the improvement during actual service delivery. Either way, it helps to observe them having the experience (see patient shadowing to learn first hand what happens).

3. Have patients tell you about their experience and then reflect on the improvement

Ask patients to tell you the story of their experiences with the improvement. Use open-ended, non-specific questions inviting the patient to re-experience it fully.

Recording patient stories on video is a very useful way of capturing critical aspects of the experience.

4. Encourage patients to reflect on the improvement

Work carefully with patients through the questions to help them evaluate the improvement. The questions need to be paced carefully so patients have time to reflect on and answer them fully. Some paraphrasing and much encouragement should be used.

5. Document your findings about the experiences carefully.

Use the biggest difference template to help you do this

6. Identify changes to improve experience

Review your findings. Identify ways to reduce negative effects and accentuate positive effects of the improvement.

The biggest difference template

Questions to ask about improvements

  • What is different about this improvement for you? 
  • Was anything else different? (Repeat until they say ?no?)
  • What effects, good and bad, did [name one difference they mentioned] have for you? (Repeat until all differences have been checked)
  • What was the biggest difference the improvement made for you?
  • What effects, good and bad, did this biggest difference have for you?
  • What were the effects during your times at home and in the rest of your life, as well as in the service?
  • What ideas and suggestions do you have about making this difference even bigger and better for you?


  • Use this tool to explore with the patient and avoid making them do all the work. The questions focus a great deal of attention on the patient and make great demands of their time, energy and emotional resilience. So encourage patients (whatever their replies), and contribute your own and others? ideas in support of those of patients you are working with.
  • Focus on learning about the effects and impacts of the prototype or actual service improvement. If you are worried about biasing the evaluation, ask a researcher or colleague to lead the session for you. However, avoid stepping away from the process; it is better to witness patients directly, and in so doing make yourself accountable, than to miss out on critical findings.
  • Having patients recall their experiences can be traumatic so make sure appropriate family and professional support is available.

Example: Communication touchpoints

During the Colorectal Cancer Service Improvement Project at Waitemata DHB, patient surveys indicated communication between staff and patients was a core service element.

In subsequent work on with the Breast and Melanoma services, communication was also found to be important.

During these projects we learned to ask patients at every opportunity: "What makes the biggest difference for you in communicating with staff?"

This single question repeatedly gave us deeper insights and richer ideas about communicating with patients. For example, we learned that when patients say 'communication', they usually mean conversations with staff. We learned that most patients favour personal, interactive, timely communications - 'the right information, at the right time, in the right way'. This prompted us to explore ideas for encouraging useful conversations between patients and staff (rather than focusing solely on better brochures, for example).

And so we learned that simple questions, such as, "What's different? and "What's the biggest difference?", along with careful listening, can lead to very rich service improvement insights and ideas.